We derive the magnetic dipole selection rules and the magnetic dipole absorption rate for a spherical semiconductor quantum dot. We find that electric dipole and magnetic dipole transitions are exclusive and therefore can be spectrally distinguished. The magnitudes of electric and magnetic absorption rates are compared for excitation with a strongly focused azimuthally polarized beam. It turns ...

Quadratic electro-optic effects (QEOEs) and electro-absorption (EA) process in a GaN/AlGaN spherical quantum dot are theoretically investigated. It is found that the magnitude and resonant position of third-order nonlinear optical susceptibility depend on the nanostructure size and aluminum mole fraction. With increase of the well width and barrier potential, quadratic electro-optic effect and ...

Electron transport experiments on two lateral quantum dots coupled in series are reviewed. An introduction to the charge stability diagram is given in terms of the electrochemical potentials of both dots. Resonant tunneling experiments show that the double dot geometry allows for an accurate determination of the intrinsic lifetime of discrete energy states in quantum dots. The evolution of disc...

Application of quantum-dot is a promising technology for implementing digital systems at nano-scale.  Quantum-dot Cellular Automata (QCA) is a system with low power consumption and a potentially high density and regularity. Also, QCA supports the new devices with nanotechnology architecture. This technique works </...

Quantum dot lasers with an active region consisting of just a single quantum dot layer have been grown using molecular beam epitaxy and characterized from 80 to 300 K. The quantum dot lasers lase from excited states over the entire temperature range. The characteristic temperature is 185$10 K over the temperature range 80—141 K and decreases to 111$2 K from 141—304 K. The effects of scattering ...

Achieving quantum dot self-assembly at precise pre-defined locations is of vital interest. In this work, a novel physical method for producing germanium quantum dots on silicon using nanoindentation to pre-define nucleation sites is described. Self-assembly of ordered ~10 nm height germanium quantum dot arrays on silicon substrates is achieved. Due to the inherent simplicity and elegance of the...

Electrons in a one-electron quantum dot were imaged in the Coulomb blockade regime at liquid He temperatures using a cooled scanning probe microscope (SPM). The SPM images are obtained by scanning a charged tip above the surface of the quantum dot and recording the conductance through the quantum dot in the Coulomb blockade regime as a function of tip position. The lowest energy level in the do...

When nanoparticle self-assembly takes place in an anisotropic liquid crystal environment, fascinating new effects can arise. The presence of elastic anisotropy and topological defects can direct spatial organization. An important goal in nanoscience is to direct the assembly of nanoparticles over large length scales to produce macroscopic composite materials; however, limitations on spatial ord...

The electronic properties of a modified magnetic quantum dot are studied. The modified magnetic quantum dot is a quantum structure that is formed by spatially inhomogeneous distributions of magnetic fields. Electrons are magnetically confined to the plane where the magnetic fields inside and outside the dot are different from each other. The energy spectrum exhibits quite different features dep...